Sewing machine



Patented Oct. 5, 1.9.43 Y

Singer Manufacturing' Company,

Elizabeth,

N. J., acorporation of New Jersey v Application Decembervl, 1941, Serial No. 422,847

' Y 5 claims. f (ci. i12-256).

This invention relates to sewing machines and more particularly to an improvement in the lubrication system employed in the sewingma-` chine.

Since the advent of high speed operation of sewing machines, of the order of 3,000 to vr5,000

stitches per minute, there has been a decided trend toward completely lubricated sewing machines, employing the splash system or various modifications thereof for automatically supplying the necessary bearing points with sucient oil to prevent excessive wear. In those machinesv in which the machine-frame provides a closed lubrication compartment in the walls of whicnis journaled one or more circularly moving shafts, trouble yhas been experienced with excessf'oil creeping Valong the shafts and through theshaftbearings to a point externally of the machine; frame where the oil is thrown off centrifugally from a member mountedon the shaft to rotate therewith, such for example as the u sualbalance-wheel for driving pulley. The oil thus thrown off soils theclothing and the like Worn by the operative and also collects on ythe top of the tablev which supports the sewing machine, thereby rendering it difficultA to handle the work to avoid contamination thereof by the oil. `The principal object of the present invention is to provide an effective seal which will prevent the escape of lubricant from a lubricant compartment in a sewing machinerthrough the shaft-bearing during rotation of the shaft.

Another object of the present invention is the provision of an oil retaining means which is simple, cheap, compact and automatically operable during the operation of the sewing machine. With the above and other objects in view,*as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth Aand illustratedin the accompanying drawing of a preferred embodiment of the invention, from which the several featuresl of the invention and the advantages attained thereby will be readily understood by those skilled in the art. l Y

In the accompanying drawing f Fig. 1 is arear elevational view, partly in section, illustrating a so-calledcup-feed sewing ma-f chine, of the type formingthe subject `of the U. S. patent to I-I. Hacklander, No. 2,277,971, issued March 31,` 1942, embodying the invention;

Fig. 2 is an elevational view, partly in section, of the belt-driven balance-wheel mountedl upon a shaft, showing the internal annular oil-colfl lecting vgrooveformed in `thehub and the plu-` rality of radial ducts for dispersing oil collected in the annular groove.

Fig. 3` is an elevational view, partly in section, of one of the bearing bushings in which the sewing machine main-shaft is journaled.

Referring more in detailto the drawing, the

present illustrated embodiment Vof the invention is shown incorpo-rated in a sewing machine cornprising a machine-frame I,` having a standardZ terminating :at its upper end in a bracket' 3. Formed within thestandard 2 is a sp1ash-1ubrication compartment 4 closed at the ,base of the standard by means of agasket `5 and a bottom cover-plate suitably attached to` the standard by screws (not shown).r L

,Disposed in vthe splash-lubrication compartmenty 4 transverselyvof the machine-frame I is a main-shaft 'Ijournaled at its opposite ends in flanged bushings 8, 9 fixed bygmeans of screws I0 in bosses II, I2 preferably cast integral with the side walls of the standard 2. Mounted upon and formed in the main-shaft l are two eccentrics I3 and It, and a crank I5, respectively, allv ofwhichare operatively connected by suitable trains of' mechanism, as clearly disclosedin the above mentioned Hacklander application, to theY balance-Wheel I6, lit will be observed in Fig. 1f, that the balance-Wheel I6 comprises a body` portion having projecting from its inner face an extension or hub I9 formed witha raised'annular rib 20 providingv an oil-sling.; Formed in the shaft-contacting surface 2l ofthe shaft-bore in the hub I9 of the balancewheel is an internal annular oil-collecting groove 22 connected by' a plurality (preferably four) of equally spaced radial ductsZS with the surface of the annular oilf-sling 20. The inner end of the balancewheel. hub I9, including the annular oil-sling ,20,projects into and is surrounded by an in-A ternal annular oil-collecting cavity 24 formed in the outer end of the bearing bushing 8.` The oil-collecting cavity 24 at its bottom is connected byan inclined drainage port 25 to the closed- -lubrication compartment 4 within the standard 2. Formed on the periphery of the balancewheel IB is .a lateral flange 26 which overlies the outerA end of the bearing bushing I6 and is tele-l scoped within the lateral flange 21 formedV on l the guard-member 28 secured between the outer.`V`

holes 3| provided in the bearing bushings 8 and.

9. The oil-hole 3l delivers the oil thus collected to the periphery of the shaft 1, thereby lubricating the shaft-bearing. To evenly distribute the oil throughout the shaft-bearing and' to assist in retaining the oil Within" the'splashlubrication compartment, the shaft 1 is formed with a spiral groove 32 cut so that during the rotation of the main-shaft l the spiral groove.

feeds the excess oil back into the splash-lubrication compartment 4.

Any oil which creeps along theouter end of the spiral groove 32 runsinto the `internal annularoil-collecting groove 22from whence it is delivered by the radial ducts 23inton the oil-collecting cavity 24,.,and then through the drainage port 25 back into the compartment 4'; beyond the end of the spiralgroove 32 is effectively collected and returned to the lubrication compartment 4. If thiscreepage of oil were not f. intercepted the oil would travel along the shaft-- bore of the` balance-wheel and be thrown offy through the set-screw `hole 33and off the outer` face of the balance-Wheel hub I9.

It willbe understood that any oil which -finds its way into the internal annular oil-collecting groove 22` in the hub I9 is delivered through the radial ducts `23 with the aid of centrifugal4 force created by the rotating hub I9; Thus, a

partial vacuum is produced in the internal annular oil-collectinggroove 22A during the operation of` the machine and any oil on the shaft between the spiral groove 32 and the hub l9oi` the balance-wheel is, in effect, pumped into the l annular voil-collecting groove 22-andhencereturned lback to'the splash-lubrication compartment. l

While I yhave illustrated the present invention as applied to a combination balance-Wheel andi driving pulley, it is to be understood that the invention isequally applicable to4 any member which might be secured on the rotary `shaft and`4 positioned adjacent `the wall dening the lubrication compartment.

Having thus set forth the nature of the invention what I claim herein is:

1. In a sewing machine having a frame provided with a plurality of Walls defining a lubrication compartment, stitch-forming and Workfeedingmechanisms, a shaft rotatably journaled in a wall of said lubrication compartment, saidl Wall having an annular oil-'collecting cavity adjacent said shaft, and a member fixed on said shaft the shaft l beyond,

In this manner anyoil which might creepV said extension within said oil-collecting cavity, and at least one oil-delivery duct formed in said extension and connecting said internal oil-collecting groove with said oil-sling.

2. In a sewing machine heaving a frame provided with a plurality of walls dening a lubrication compartment, stitch-forming and Workfeeding mechanisms, abearingfbushingxed in said wall and: having an.internalA oil-collecting cavity formed therein, a rotary shaft journaled insaid bearing-bushing, and a member disposed externally of said lubrication compartment and fixed-on said shaft to rotate therewith, the improvement which consists in the provision of meansfor preventing the escape of oil through saidshaft-bearingl and onto said member, comprising a hub formed on said member, said hub provided With a shaft-bore and an internal annular'oil-collecting groove in said shaft-bore adjacent said bearing-bushing, said shaft-bore substantially in contactwith saidishaft on opposite sides of saidfoil-collecting groove, an oil-sling provided on 'the periphery of said Ihub Within-the' confines of said oil-collecting cavity in said bearing-bushing, andat least one oil-delivery duct formed in'said hub and connectingsaid internal oil-collecting groove yWithsaid oil-sling-` 3'. In aisewingmachine having a frame pro-` vided With ar plurality of'Wa-lls defining a lubri cation compartment, stitch-forming and'- Workfeeding mechanisms, a-bearingbushingxed inJ said wall andhaving an internal annular oil-H collecting cavity formed therein, means for returning `oil collected in ysaid cavity to said lubri- J` cation compartment; arotary shaft journaled inl externally of said' lubrication compartment, the y65 improvement which consists in the provision; of

means for preventing the escape of oil 'through' said shaft-bearing and onto said memberycomprising, an extension on said `member having;

formed therein a` shaft-bore and an internal oilcollecting groove in that end of said shaft-boreadjacent said lubrication compartment Wall, said" shaft-bore substantially in contact'with said shaft on opposite sides of Vsaid oil-collecting said bearing-bushing;y andfa member disposed externally of 'fsadilubricationf compartment and xedon saidshaft'torotate therewith, the improvement which consistsv in theprovision ofmeans for `preventing' the-'escape of oil' throughsaidfshaftibearingand `onto said member, comprising; a hubformed on said member, said'hub' having formed therein a shaft-bore and an internal annular oil-collecting groove in said shaftb'ore adjacent said 'bearing-bushing, ysaid shaftbore substantially in contact with'said shaft on opposite sides of said oil-collecting. groove, a raised `rib provided on the periphery' of said hub and disposed withinthe confines of said `oil-col- 'lectingcavity toforman oil-sling, and at least one oil-delivery duct formed in said hub and connecting,y said.. internal oil-collecting. groove with said rib.

4.y An improved oil-sealingmeans adaptedffor 'use ina sewing r,machine having aframe provided-with a .plurality of lWalls dening a lubrication compartment, stitch-forming and Workfeedingvmechanislns,A and a rotaryshaft extend- A ing through one'of-thewalls ofsaid lubrication compartment, comprisingfa Vbushing adapted toI beimounted in awall of said=lubricationcompartment andprovidea bearing for said rotary shaft,- said bushinghaving 1, ani internal annular oil-collecting cavity surrounding saidshaft and a duct Y for draining said cavity, a member adapted to be fixed to saidlshaft =toirotatewtherewith and having 'one i of .its ends :extendingginto said oil-collecting' cavityi saidmember `having a shaft-bore land 'antinternal annular oil-collectingl groove f in 1 one duct in said member connecting said internal oil-collecting groove with said oil-sling.

5. An improved balance-wheel adapted for use in a sewing machine having a lubrication compartment, a bushing xed in said lubrication com.

partment provided with an internal oil-collecting cavityfand a rotary shaft extending through saidy lubrication compartment and journaled in said bushing, comprising, a body-portion, an extension on said body-portion adapted to project into said oil-collecting cavity, said extension formed with a shaft-bore and an internal annular oilcollecting groove in said shaft-bore,1said shaftbore on opposite sides ofsaid oil-collecting groove t adapted to substantially contact said shaft, an 

